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Clay was used as a mortar in brick chimneys and stone walls where protected from water. Clay, relatively impermeable to water, is also used where natural seals are needed, such as in pond linings, the cores of dams, or as a barrier in landfills against toxic seepage (lining the landfill, preferably in combination with geotextiles). [33]
In clay mineralogy, smectite is synonym of montmorillonite (also the name of a pure clay mineral phase) to indicate a class of swelling clays. The term smectite is commonly used in Europe and in the UK while the term montmorillonite is preferred in North America, but both terms are equivalent and can be used interchangeably.
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al 2 Si 2 O 5 4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals form in the presence of water [1] and have been important to life, and many theories of abiogenesis ...
While decorated ware was usually adorned using cobalt oxide, decorative techniques such as incising were also used. Flowering plants, birds, or other decoration were cut into the leather-hard clay using a stylus to produce detailed recessed images on the vessels; these were usually also highlighted in cobalt.
Kaolinite (/ ˈ k eɪ. ə l ə ˌ n aɪ t,-l ɪ-/ KAY-ə-lə-nyte, -lih-; also called kaolin) [5] [6] [7] is a clay mineral, with the chemical composition Al 2 Si 2 O 5 4.It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO 4) linked through oxygen atoms to one octahedral sheet of alumina (AlO 6).
The first recorded use of medicinal clay is on Mesopotamian clay tablets around 2500 BC. Also, ancient Egyptians used clay. The Pharaohs’ physicians used the material as anti-inflammatory agents and antiseptics. It was used as a preservative for making mummies and is also reported that Cleopatra used clays to preserve her complexion. [1] [2]
Pinch pots are the simplest and fastest way of making pottery, [1] simply by pinching the clay into shape by using thumb and fingers. Simple clay vessels such as bowls and cups of various sizes can be formed and shaped by hand using a methodical pinching process in which the clay walls are thinned by pinching them with thumb and forefinger. It ...
The ceramic use of ball clays in Britain dates back to at least the Roman era. More recent trade began when a clay was needed to make tobacco pipes in the 16th and 17th century. [8] In 1771 Josiah Wedgwood signed a contract for 1,400 tons a year of ball clay with Thomas Hyde of Purbeck, enabling the production of thinner-walled ceramics. [9]